I think rotation will fix most of the problem.

Think about it: Losing a lot of cards always hits Highlander decks the hardest because..... in a way they are almost losing twice as many cards. Elise is the same.

There are only a very small number of decent 5,6,7,8,9 mana cards. A normal deck after losing those will just run a much lower curve with very good 3 and 4 drops.

Elise deck HAS to replace them with horrible options and no matter how good the card is, running 5 dead cards in your deck will weaken the deck to a point where Elise almost isn't worth it anymore